摘要
简要介绍了ITU-T G.723.1双码率编码器算法原理,以及ADI公司的定点DSP芯片Blackfin533的硬件特性,在基于H323协议的可视电话系统的开发环境下,讨论了G.723.1语音编码器的定点实现方案及关键技术,并给出了定点C语言程序和全汇编程序实现时有效的优化策略。试验结果表明,定点的G.723.1语音编码器完全通过ITU-T标准中的各种测试矢量,且满足系统的实时性要求。
The algorithmic principle of G. 723.1 dual rate speech coder and the hardware property of Blackfin533 digital signal processor of the Analog Devices Inc. are introduced in this paper. In the develop environment of a visual phone system based on H323 Standard, the key technology and the scheme of fixed-point implementation of G. 723.1 coder are discussed and then the optimized techniques designed with the C program language and assemble language are given. Experiments results show that fixed- point G. 723.1 coder passes all ITU-T G. 723.1 test vector and meets the demand of real time system.
出处
《计算机与数字工程》
2006年第1期107-110,148,共5页
Computer & Digital Engineering
